Environmentally Sustainable Development Studies and Monograph Series No. 17. A 1995 publication from the World Bank, Monitoring Environmental Progress: A Report on Work in Progress, generated great interest in the use of indicators to measure the pace and direction of change in environmentally sustainable development. In particular, the attempts to define what it means to be wealthy or poor by recognizing that a countrys wealth is the combination of various forms of capital--produced, natural, and human resources--led to new thinking on what constitutes wealth and how it might be measured. The current document, Expanding the Measure of Wealth: Indicators of Environmentally Sustainable Development, extends the earlier analysis by highlighting portfolio indicators for tracking a countrys progress toward sustainable development. These include new estimates of national wealth and genuine savings, a detailed analysis of changes in subsidies that have environmental consequences, and progress on the conceptual foundations of social capital. The new estimates reinforce the importance of the natural resource base of all economies as well as the fundamental role of human resources, including both human capital and the more difficult to define concept of social capital.